NR-U Random Access Preamble Transmission via LBT Segmentation
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Solution Overview
Problem
Current NR-U-based random access technologies experience delays due to the lack of a perfect solution for reducing access time, as terminals can only send a random access preamble once and must wait for the next opportunity if the first attempt fails, leading to inefficiencies in wireless communication systems.
Innovation Solution
Implementing a method where a terminal performs random access preamble transmission in a first RO in an LBT mode before arrival, and if no RAR is received, it continues to transmit in a second RO within a predetermined RAR time window, allowing multiple attempts within a single random access process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a terminal performs random access preamble transmission only once in the first RO, then the device complexity is reduced, but the access time increases due to waiting for the next opportunity if the first attempt fails
Solution Approach 1:
The patent segments the random access process into multiple transmission opportunities (first RO and second RO) within a single random access process. The terminal can attempt preamble transmission in the first RO, and if unsuccessful, continue transmission in the second RO without initiating a completely new random access process, thereby reducing access time while maintaining manageable complexity through structured segmentation.
Solution Approach 2:
The patent prepares multiple RO opportunities in advance within the random access process. The terminal is pre-configured with knowledge of additional ROs where it can retry transmission if the first attempt fails, eliminating the need to wait for the next random access process and reducing overall access time.
2Ease of operation
If a terminal waits for the next random access opportunity after failed preamble transmission, then the protocol simplicity is maintained, but the productivity decreases due to access delays
Solution Approach 1:
The patent merges multiple transmission opportunities (first RO and second RO) into a single random access process. The terminal can perform preamble transmissions in both ROs without the base station needing to distinguish between different random access processes, maintaining protocol simplicity while improving access efficiency through multiple attempts.
Solution Approach 2:
The patent makes the random access process universal by allowing it to accommodate multiple preamble transmission attempts within a single process. The base station handles both first RO and second RO transmissions using the same random access response mechanism, improving productivity without requiring separate specialized protocols for each attempt.
3Productivity
If multiple preamble transmissions are allowed within a single random access process, then the access efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent implements periodic transmission opportunities (first RO and second RO) within the random access process. The terminal attempts transmission at regular intervals defined by the RO structure, improving access efficiency through multiple attempts while keeping complexity manageable through the periodic, predictable nature of the transmission opportunities.
Data Source
AI summary
A method for transmitting a random access message, a device and a non-transitory computer-readable storage medium thereof are provided. The method includes that in a random access process based on an unlicensed channel, a terminal performs random access preamble transmission in a first Rach Occasion (RO) in a Listen Before Talk (LBT) mode before arrival of the first RO. If the terminal does not receive a Random Access Response (RAR) returned by a base station before arrival of a second RO, the terminal continues to perform random access preamble transmission in the second RO in the LBT mode.